The inspection device of the swing forging apparatus includes an inspection tool and a laser irradiation surface. When inspecting the swing forging apparatus, the inspection tool is supported to the head to which the processing roll is not supported, with a substantially same condition as the processing roll, and the inspection tool has a function of emitting a laser beam onto a central axis of the inspection tool. When inspecting the swing forging apparatus, the laser irradiation surface is arranged so that a relative position of the laser irradiation surface to the head in an axial direction of the head can be changed and the laser beam can be irradiated to the laser irradiation surface.

Rotary forging for forming a hub-side face spline is started in a state in which a caulking section is made to come in contact with a flat surface section that is an inner end surface of an inner ring in an axial direction and a chamfer. In addition, a contact portion between an inner end surface of the caulking section in the axial direction and a processing surface of a roll at the beginning of the rotary forging overlaps a contact portion between the caulking section and the flat surface section and the chamfer of the inner ring in the axial direction.

A method of manufacturing a rotating bearing unit includes to cause one end surface in the axial direction of the forming punch (46), formed by combining a plurality of punch elements (46, 46) divided in the circumferential direction, which are displaceable in the axial direction and which are not displaceable in the circumferential direction, and having a processing teeth (44, 44) at one end surface in the axial direction, to face the other end surface of the caulking section (20) in the axial direction. In this state, rolls (30a) are rotated about the central axis (a) of the hub main body (8) while pressing the other end surface of the forming punch (46) in the axial direction with a pressing surface (43) of the roll (30a) having a central axis () that is inclined with respect to the central axis () of the hub main body (8).

A plurality of press rolls (33) each having an inclined roll central axis (6) are used. Each of press rolls (33) and a bub ring (22z) are relatively rotated while pressing a roll processing surface portion (34) of each of the press rolls (33) against a plurality of locations of a tubular portion (25) of the hub ring (22z) in a circumferential direction to plastically deform the tubular portion (25).

A method for manufacturing a rolling bearing unit is provided to periodically reciprocate a stage (38) in a vertical direction by rotating and driving a servo motor (44) while rotating a roll about a central axis of a hub main body using a roll driving motor (43) in a state in which a processing surface of the roll is pressed against other end surface of a caulking section in an axial direction. A period of the reciprocation is restricted by a relation between a rotation position of the roll about the central axis of the hub main body and an engaged state between concave sections, which are sections between a plurality of processed teeth formed in the processing surface of the roll, and a face spline tooth formed by the concave section.

A method of manufacturing a rolling bearing unit for supporting a wheel includes detecting a current value flowing through an electric motor (19) configured to drive a roll (22) and determining a time to terminate a caulking process on the basis of the detected value when a caulking section (13) is formed by pressing the roll (22), inclined with respect to a central axis of a hub main body (7) and supported in a rotatable state about a central axis of the roll, against a cylindrical section (12), installed on an inner end portion of the hub main body (7) in the axial direction, while the roll (22) is rotated about the central axis of the hub main body (7).

Construction is achieved that is capable of preventing the formation of radial streaks in the tip-end surfaces of teeth of hub-side face splines 21. When a swing center distance is taken to be L, a swing angle that is the inclination angle of the center axis of a roll 30 with respect to a main hub body 8 is taken to be , the pitch diameter of the hub-side face splines 21 is taken to be D.sub.h, the number of teeth of the hub-side face splines 21 is taken to be N.sub.h, and the number of teeth of a processing surface 31 of the roll 30 is taken to be N.sub.r, the position relationship of the main hub body 8 and the roll 30, or in other words, at least one of the swing center distance L, the swing angle , and the pitch circle diameter D.sub.h is regulated so that the relationship Nh/Nr=cos +(2L/D.sub.h).Math.sin is satisfied.

A method and tool for obtaining face teeth having a plurality of radial teeth on an annular collar of an inner ring of a wheel hub; in which annular roughed-out face teeth are first formed on the collar coaxial with an axis of symmetry (A) of the collar and having a plurality of radial first teeth arranged in a crown and alternating at constant pitch with a plurality of radial first concavities; then a shaping tool comprising a pressing head provided with annular calibration face teeth is axially pressed onto the collar to engage with the annular roughed-out face teeth, second radial concavities of the annular calibration teeth each being delimited by a bottom wall having a rounded circumferential profile exactly reproducing in negative the rounded circumferential profile of the tips or ridges of the radial teeth of the required face teeth.

A rotary press device (33) includes a restriction section (36) configured to restrict a motion of a roll (30) around a central axis of a roll (30) against movement of the roll (30) around a central axis of a hub main body (8) during rotary forging. In an example, the restriction section (36) has guide teeth (44) meshed with teeth formed on a processing surface of the roll (30).

The method for the manufacture of a spoke for spoked wheels including a step of forming a head of the spoke at a longitudinal end of the shank thereof by equipment for the plastic deformation of the end of the shank, wherein the plastic deformation is obtained by maintaining the shank in relative rotation to the equipment.